1 . Field of the Invention
The present invention relates to a prism sheet and a liquid crystal display having the same. More particularly, the present invention relates to a prism sheet and a liquid crystal display having the same, capable of representing high light collecting efficiency.
2 . Description of the Related Art
Recently, as various electronic appliances such as mobile phones, PDAs (Personal Digital Assistants), computers and large-scale televisions have been developed, demands for flat panel display devices applicable to the electronic appliances have been gradually increased.
The flat panel display devices, such as LCDs (Liquid Crystal Displays), PDPs (Plasma Display Panels), FEDs (Field Emission Displays), VFD (Vacuum Fluorescent Displays), EPDs (Electrophoretic Displays), and the like, have been actively studied. Among them, LCDs have been currently spotlighted in terms of mass production, simple driving scheme and high-quality images.
LCDs are display apparatuses using optical anisotropy of liquid crystals, and display images by controlling light transmittance of the liquid crystals using an electric field.
Such an LCD includes a liquid crystal panel to display an image. Since the liquid crystal panel is a non-emissive device, the LCD additionally requires a backlight unit to supply light to the liquid crystal panel.
The backlight unit includes optical sheets such as a diffusion sheet, a prism sheet, and a protective sheet to increase light transmittance of the liquid crystal panel. Recently, the diffusion sheet or the protective sheet has been removed from the backlight unit to reduce the manufacturing cost. However, if the optical sheet such as the diffusion sheet or the protective sheet is removed from the backlight unit, not only is there an increase in the loss of light according to exit angles of light output from a light guide plate, but a viewing angle may be expanded and brightness may be reduced. Accordingly, the structure of a prism sheet capable of raising light collecting efficiency by increasing brightness without degrading the viewing angle is required.